When I started doing experimental pneumoconiosis research more than 50 years ago, Selye's concept of stress was the leading explanation of pathogenesis of connective t- sue andofvascular disease. Thisled me toattempt experimentalprophylaxisby ad- nistering antistress hormones to rats and mice injected with particulate matter. Once my field of research changed from pulmonary to cardiovascular and cerebral hypoxic states, I aimed my experiments at oxidative stress during reperfusion following - poxia. In addition to electron microscopy and histochemistry, I also made use of b- physics (a field that my younger daughter is qualified to lecture on) to study phot- mission from reactive species arising from crushing quartz particles and engulfing particulate matter by mononuclear phagocytes. The question of carcinogenesis by - spirable industrial waste - particles and vapours - led to the topics of oxidative DNA lesions, chromosomal breaks and mutagenicity. I wish to gratefully acknowledge all those who have helped in experimental work and in the preparation of this book: Prof. H. Brettschneider (Essen), Prof.

L. Vollrath (Mainz) and Prof. U. Bleyl (Mannheim), who provided me with access to their el- tronmicroscopy facilities andmuchgoodadvice. Iowe thanks to Prof. W. J. Zeller (German Cancer Research Centre, Heidelberg) for enabling me to do biophysical studies on photoemission by reactive species.